Formaldehyde organometallic compound reaction

Reaction of organometallic compounds with carbonyl compounds a. primary alcohols from methanal (formaldehyde)... 

The reaction of organometallic compounds with formaldehyde results in primary alcohols. In the electrostatic potential maps of the example below, the electron-rich (orange-red) carbon of the butylmagnesium bromide is seen to attack the electron-poor (blue) carbon of formaldehyde to give 1-pentanol. 

Prior to the development of methods for caiTving out the direct reaction of fomialdehyde vdth acetydene or monosubstituted acetylenes (page 237), the only satisfactory procedime for preparing acetylenic alcohols from formaldehyde involved the intennediate preparation of organometallic compounds. Substituted pi Opargyl alcohols are obtained in yields of 70 per cent or better by reaction of monosubstituted acetylenic Grignard compounds with gaseous formaldehyde ... 

Indium-promoted organometallic reactions are greatly accelerated in water, especially when the coreactant carbonyl compound also has good water solubility. Otherwise, aqueous tetrahydrofuran can be used. To date, indium is the most effective metal for promoting Barbier-type reactions under aqueous conditions. As illustrated here, this is of particular value where formaldehyde is concerned, since the need to generate monomeric formaldehyde by thermal cracking is avoided. 

Since carbon dioxide is a thermodynamically stable, highly oxidized compound, its synthetic utilization requires some kind of a reduction -reaction with molecular hydrogen is a distinct possibility. Stepwise reduction of C02 with H2 may yield formic acid, formaldehyde, methanol and finally methane, together with CO or Fischer-Tropsch-type derivatives as shown on Scheme 3.42. In aqueous organometallic catalysis the most common product of such a reduction is formic acid. Formation of carbon monoxide, formaldehyde, and methane has already been reported, however, methanol and Fischer-Tropsch type products were not observed. 

An organometallic route to muscarine derivatives has been developed (Scheme 1). Reduction of the aa -dibromo-ketone (1) with Fe2(CO)9 in the presence of DMF provided the furanone (2) in good yield. Acetylation of (2) afforded the corresponding enol acetate, which upon Mannich reaction with dimethylamine and formaldehyde gave the furan derivative (3). Deacetylation followed by dissolving-metal reduction and quaternization with methyl iodide gave two isomeric 4-methyl-muscarine salts (4). These compounds showed physiological properties characteristic of the muscarine alkaloids. 

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